Apparatus for Reducing Nitrogen Oxide in Exhaust Pipe

Abstract

An apparatus for reducing nitrogen oxide in an exhaust pipe, may include a nitrogen oxide sensor that is mounted in the exhaust pipe and that measures amount of the nitrogen oxide in exhaust gas, a nozzle that is disposed on the exhaust pipe to be spaced apart from the nitrogen oxide sensor to a downstream side of the nitrogen oxide sensor by a first predetermined length and that injects urea corresponding to the amount of the nitrogen oxide, a mixer that mixes the urea with the exhaust gas and that is disposed at a downstream side of the nozzle on the exhaust pipe to be spaced apart by a second predetermined length from the nozzle, and a de-nitrification catalyst reaction device that is disposed at a downstream side of the mixer on the exhaust pipe, purifies the nitrogen oxide, and includes an inlet portion having a predetermined length.

Dependencies are inferred from the claim text.